Restorative dentistry is replacing missing tooth structure due to fracture or decay with man-made material to replace the function, shape and aesthetics of the tooth. When there is substantial amount of tooth structure missing, filling restorations do not provide functional replacement that can last long term. When that happens, a cap in a shape of the restoring tooth is used to be placed on a top of a 1-2 mm shaven reduced tooth structure. I prefer to use all ceramic crowns that do not contain any metals. I believe that presence of nickel among other metal elements in the old crowns do and can affect the health of adjacent gingival health. Metal free margin also will provide potentially better aesthetics.